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Biomedical subjects

E Wennberg

Publications and source records attributed to E Wennberg.

At least 19 recordsLinked to original sources
PubMed2002

Randomized clinical study of the prevention of pulmonary complications after thoracoabdominal resection by two different breathing techniques.

BACKGROUND: Pulmonary complications are frequently seen after thoracoabdominal resection of the oesophagus. The aim of this study was to compare the effects of two different breathing exercise regimens applied in the immediate postoperative period on the risk of pulmonary insufficiency after thoracoabdominal resection. METHODS: Seventy patients undergoing thoracoabdominal resection for cancer of the oesophagus and cardia were randomized after operation to breathing exercises by inspiratory resistance-positive expiratory pressure (IR-PEP) (n = 36) or continuous positive airway pressure (CPAP) (n = 34). The study groups were well matched for all relevant clinical and demographic data. RESULTS: Respiratory function deteriorated significantly immediately after operation; the lowest values of forced vital capacity and peak expiratory flow were measured during the first postoperative day and oxygen saturation was lowest on days 4-6. Significantly fewer patients in the CPAP group required reintubation and prolonged artificial ventilation (P < 0.05). There were minor non-significant differences between the study groups with respect to respiratory and other postoperative variables, usually in favour of CPAP. CONCLUSION: Provision of CPAP in the immediate postoperative period decreased the risk of respiratory distress requiring reintubation and the need for artificial ventilation compared with breathing exercises by IR-PEP.

Cardia↗
PubMed2000

Anaesthesia, recovery and postoperative nausea and vomiting after breast surgery. A comparison between desflurane, sevoflurane and isoflurane anaesthesia.

BACKGROUND: Whereas induction and recovery will occur more rapidly with the new low soluble anaesthetics than with isoflurane, the quality of anaesthesia and recovery with special emphasis on postoperative nausea and vomiting (PONV) is not well known. METHODS: In an open (peroperatively), double-blinded (postoperatively), randomised controlled study, we assessed anaesthesia characteristics, recovery and 24 h PONV after breast surgery comparing isoflurane, desflurane and sevoflurane. RESULTS: There were no significant quality differences between the three agents during anaesthesia and recovery except for the incidence of PONV in the postanaesthesia care unit (PACU). The PONV rate (24 h in PACU and ward) was higher in the desflurane group (67%) than in the isoflurane group (22%), (P<0.01). The corresponding PONV rate for sevoflurane was 36%. CONCLUSION: The quality of anaesthesia, time to opening of eyes and influence on respiration was similar with all three anaesthetics. As the emergence from anaesthesia did not differ significantly between the three agents, the choice of agent could be based on PONV rate and price. Desflurane had a significantly higher 24 h PONV rate than isoflurane. Early PACU PONV rate was significantly (P<0.05) lower for the more soluble isoflurane (4%) than for the low soluble gases, desflurane and sevoflurane together (28%). The result of this study does not give a rationale for a transition to the new low soluble agents in breast cancer surgery.

Anesthesia Recovery Period↗
PubMed1999

Hypertonic saline without or with dextran-70 in the treatment of experimental acute myocardial ischemia and reperfusion.

OBJECTIVE: To evaluate the effects of treatment with hypertonic saline without (HS) or with dextran (HSD) on cardiac function and myocardial damage during reperfusion after acute myocardial ischemia. DESIGN: A prospective, randomized, controlled study. SETTING: Animal laboratory at a university medical center. SUBJECTS: Three-month-old male, crossbred (Swedish landrace, Yorkshire, and Hampshire) pigs. INTERVENTIONS: The pigs were anesthetized and catheterized. A mid-sternal thoracotomy was performed, the pericardial sac was opened, and the left anterior descending artery was dissected free and occluded for 45 mins. A 10-min treatment period with 4 mL/kg HS (7.5%), HSD (7.5%/6%), or normal saline (0.9%) was started 5 mins before reperfusion. After a reperfusion period of 240 mins, biopsies from the ischemic area were taken. Thereafter, the hearts were excised and subjected to a staining procedure (triphenyltetrazoliumchloride and Evan's blue), and the left ventricle was sliced for assessment of the size of the infarcted area and the area at risk. MEASUREMENTS AND MAIN RESULTS: Central hemodynamics and myocardial performance were monitored before, during, and for 240 mins after 45 mins of acute left anterior descending artery occlusion. Alterations in blood chemistry and serum levels of markers of myocardial damage were repeatedly analyzed during the experimental procedure. Biopsies from the injured myocardium were analyzed for adenosine triphosphate, adenosine 5'-diphosphate, adenosine monophosphate, creatine phosphate, lactate, and glucose. Infarct sizes and areas at risk were planimetrically quantified. HS was not found to enhance, but rather to depress, cardiac performance at reperfusion, whereas HSD improved hemodynamics and myocardial contractility. HS or HSD administration was not found to increase the ischemia-induced myocardial damage. CONCLUSIONS: The administration of HSD but not HS will improve hemodynamics and myocardial performance during reperfusion after 45 mins of myocardial ischemia. The documented myocardial ischemic injury was not affected by any of the fluid therapies. Therefore, the present data do not support previously suggested detrimental effects of HS on myocardial ischemic injury.

Analysis of Variance↗
PubMed1994

Haemodynamic changes during epidural caesarean delivery.

The cardiovascular changes during epidural caesarean delivery were studied, using a non-invasive cardiac output monitor (BoMed NCCOM3-R7). Two different regimens were used to control hypotension (A = 15 ml/kg of 3% dextran 70, B = 7.5 ml/kg of 3% dextran 70 followed by an infusion of 17.5 mg of ephedrine). Cardiac index (CI) and heart rate (HR) increased after delivery and oxytocin administration (P < 0.001) and maximum values were recorded 1-1.5 min after administration of oxytocin. The maximum increase in CI was 76% (A) and 117% (B), in HR 42% (A) and 56% (B), and in SI 23% (A) and 47% (B) compared with values before anaesthesia. The increase in cardiac output after delivery was greater than that measured previously, which might be because impedance cardiac output is a continuous method. It is also suggested that the most pronounced changes are augmented by the use of a bolus injection of 10 units oxytocin i.v.

Journal Article↗
PubMed1993

Efficacy of osmolality and ionic composition of resuscitation fluids for treatment of acute blood loss in the spontaneously hypertensive rat (SHR).

The spontaneously hypertensive rat (SHR) has a deficient glucose mobilization in response to blood loss. Treatment of blood loss with hypertonic glucose might consequently be advantageous in SHR, but the importance of osmolality as compared to ionic composition of resuscitation fluids is still not fully elucidated. Therefore, SHR (n = 32) were subjected to hemorrhage (30% of calculated blood volume) followed by treatment with (1) hypertonic saline (HS; 4.5 ml/kg of 7.5% NaCl, 2,400 mOsm/L), (2) hypertonic glucose (HG; 4.5 ml/kg of 42.3% solution, 2,400 mOsm/L), and (3) normal saline (NS; 37.5 ml/kg of 0.9% NaCl) to provide an equal sodium load as with HS. All fluid regimens increased (P < 0.001 vs. control) mean arterial pressure (MAP). Hemodilution was more pronounced after HS and NS than after HG. Hypernatremia was evoked by HS. The hyperglycemic response to hemorrhage was intensified by HG, but it was accompanied by increased blood lactate levels. All three treatment regimens prolonged posthemorrhagic times until death (P < 0.01-0.05) (mean values: NS 363 min; HS 170 min; HG 146 min; nontreated controls 60 min). It is concluded, on the basis of hemodynamic, metabolic, and times-until-death data, that although treatment with small-volume HS seems superior to small-volume HG, an equal load of sodium given as NS is more effective for resuscitation after blood loss than HS in SHR.

Acute Disease↗
PubMed1992

Colloid (3% Dextran 70) with or without ephedrine infusion for cardiovascular stability during extradural caesarean section.

Using a non-invasive cardiac output monitor (Bo-Med NCCOM 3-R7), we have compared cardiovascular responses, degree of haemodilution and incidence of nausea during extradural Caesarean section in healthy non-labouring mothers given either ephedrine 17.5 mg and 3% Dextran 70 7.5 ml kg-1 before delivery (group A) or volume loading with Dextran 15 ml kg-1 without infusion of ephedrine (group B). Smallest systolic arterial pressures before delivery were 114 (SEM 4) mm Hg (group A) and 105 (5) (group B). There were no significant differences between the groups in mean arterial pressure, heart rate, systemic vascular resistance or central venous pressure, while cardiac output increased more with the ephedrine infusion (P less than 0.05). Haemodilution was 8% in group A and 16% in group B at the time of delivery. Ephedrine infusion was associated with a smaller incidence of nausea (P less than 0.01). Umbilical arterial pH values were not different between the two groups. We conclude that infusion of ephedrine, combined with low volume colloid administration, is a safe alternative to more extensive colloid volume expansion for control of hypotension and provides effective prophylaxis against nausea during extradural Caesarean section in healthy non-labouring mothers.

Adult↗
PubMed1991

Local luteolytic effect of prostaglandin F2 alpha in the human corpus luteum.

OBJECTIVE: To evaluate the effects of prostaglandin (PG)F2 alpha on human corpus luteum (CL) function in vivo. DESIGN: The effects of a single injection of PGF2 alpha into the CL was studied. SETTING: The patients underwent elective surgery at the Department of Obstetrics and Gynecology, Sahlgrenska Hospital, University of Göteborg, Sweden. PARTICIPANTS: Twenty women with regular menstrual cycles undergoing laparoscopy for legal sterilization with tubal clips volunteered for the study. INTERVENTIONS: Prostaglandin F2 alpha (3 mg) was injected through the abdominal wall into the CL. In control cases, vehicle was injected into the CL or PGF2 alpha into the contralateral ovary. MAIN OUTCOME MEASURE: After the injections, serum was analyzed for progesterone (P) and luteinizing hormone using fluoroimmunoassay and enzyme-immunoassay, respectively. Menstrual data were recorded. RESULTS: In contrast to control cases, intraluteal injection of PGF2 alpha caused both an immediate fall of greater than 30% in serum P and a shortening of the luteal phase by 2 to 5 days. Luteinizing hormone varied independently of the changes in serum P levels. CONCLUSION: The results suggest a local role for PGF2 alpha in human luteolysis.

Adult↗
PubMed1990

Evaluation of brain damage in a rat model of neonatal hypoxic-ischemia.

In spite of improvements in obstetric and neonatal care, hypoxic-ischemic brain damage with severe neurologic disability is still a clinical reality. A model in 7-day-old rats has been introduced to study the pathophysiology of perinatal hypoxic-ischemic brain damage. Unilateral brain damage is produced in the cerebral cortex, striatum and hippocampus, i.e. a similar distribution as is often seen in human asphyxiated neonates. In the present investigation the model was evaluated further by comparing three different methods to assess the brain damage: weighing the hemispheres, morphometry and somatosensory evoked potentials. Seven-day-old rats were subjected to unilateral carotid artery ligation followed by 2 h of hypoxia (7.7% O2 at 36 degrees C). After 2 h of hypoxic-ischemia pCO2 and pO2 decreased in mixed arterial/venous blood. The evaluation of the damage 2 weeks after the insult, demonstrated close correlation between morphometry and weighing (r = 0.836, P less than 0.01). The amplitude of evoked potentials correlated to the other parameters (r = 0.814, P less than 0.01 and r = 0.824, P less than 0.01 respectively) and displayed a greater relative attenuation than the other methods but with a more pronounced variability. These results indicate that the degree of brain damage can be assessed by weighing for screening purposes.

Aging↗
PubMed1990

Comparison of Ringer's acetate with 3% dextran 70 for volume loading before extradural caesarean section.

We have studied haemodilution and cardiovascular responses to i.v. hydration with either 3% dextran 70 (Dx70) or Ringer's acetate using a non-invasive cardiac output monitor (BoMed NCCOM3-R7) in 40 healthy parturients undergoing Caesarean section under extradural anaesthesia. Haemodilution was more pronounced, and central venous pressure, mean arterial pressure and cardiac index maintained at greater values, after treatment with Dx70. Colloid osmotic pressures (COP) decreased by 1.7 mm Hg after loading with 3% Dx70, and by 5.6 mm Hg in mothers treated with Ringer's acetate (P less than 0.001). The transthoracic fluid index decreased more after hydration with Ringer's acetate (P less than 0.001), indicating an increase in lung water. In spite of these maternal changes, there were no differences in neonatal bioimpedance or values of haemoglobin, PCV, albumin and COP in umbilical cord blood, and only one case of respiratory distress. We conclude that colloids may be preferable to crystalloids for circulatory preload for extradural Caesarean section, as greater haemodynamic stability was maintained and increases in lung water avoided.

Adult↗
PubMed1988

The excitatory amino acid antagonist kynurenic acid administered after hypoxic-ischemia in neonatal rats offers neuroprotection.

The neuroprotective effect of kynurenic acid, an unspecific antagonist of excitatory amino acid receptors, was evaluated in a model of hypoxic-ischemia in neonatal rats. One-week-old rats were subjected to ligation of the left carotid artery and exposure to 7.7% O2/92.3% N2 for 2 h. Kynurenic acid (300 mg/kg) was administered i.p. immediately after the period of hypoxic-ischemia in one group (n = 32) and compared with saline-treated (n = 27). After 2 weeks the rats were sacrificed and the brain damage evaluated by comparing the weight of the lesioned and unlesioned hemispheres. In rats receiving kynurenic acid the reduction in weight of the lesioned hemisphere was 25.4 +/- 3.3% as compared to 37.8 +/- 3.6% in saline-treated controls (P less than 0.001). The results suggest that excitatory amino acids are involved in the development of postischemic damage in the immature brain.

Animals↗
PubMed1987

Hepatic arteries in normotensive and spontaneously hypertensive rats. A morphometric study.

The media thickness (m), luminal radius (r) and m/r ratio were determined in the hepatic arterial trunk and in intra-hepatic arterial branches as was the number of arteries per cm2 sectioned liver tissue in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto controls (WKY). The cross-sectional vessel parameters were calculated for a standardized condition, in which the internal elastic membrane is smooth and circular. Both intra-hepatic arterial branches and the hepatic arterial trunk showed significantly higher m/r ratios in SHR than in WKY controls. The luminal radius of the hepatic arterial trunk was larger in SHR than in WKY (P less than 0.05). The number of arteries per cm2 sectioned liver tissue was greater in SHR (P less than 0.05). It is suggested that the consequences of the increased m/r ratio in hepatic arteries of SHR are counteracted to some extent by an increased vascularization, but that during hypovolaemia and compensatory vasoconstriction, a greater decrease in hepatic arterial blood flow occurs in SHR than in WKY.

Animals↗
PubMed1986

Liver susceptibility to ischaemia in spontaneously hypertensive rats.

Blood loss has previously been shown to be more detrimental for spontaneously hypertensive (SHR) than for normotensive Wistar-Kyoto (WKY) rats. To evaluate whether this decreased tolerance to blood loss is due to disturbances in circulatory control or to alterations in cellular function caused by the hypertensive disease, SHR and WKY were subjected to complete liver ischaemia. During a 45-min period of ischaemia as well as after 4 h of reflow, the liver content of ATP, glycogen, glucose and lactate was determined. Liver ATP decreased to 15% and liver glycogen to 30% of initial levels, while liver glucose increased 6-fold and liver lactate 13-fold during the ischaemic period in both SHR and WKY. Following 4 h of reflow, ATP was restored to 11.5 +/- 1.7 mumol X g protein-1 (56% of initial level) in SHR and to 15.2 +/- 1.3 (76%) in WKY. The levels of lactate and glucose returned to control levels after the reflow period while the glycogen stores were further depleted in SHR as well as WKY. No difference between SHR and WKY in cellular metabolic function during the ischaemic period could thus be demonstrated, and the postischaemic recovery was not significantly different. It is concluded that hypertensive disease does not seem to change the ischaemic tolerance of liver cells to any considerable extent.

Animals↗
PubMed1984

The response of the awake spontaneously hypertensive rat (SHR) to acute blood loss.

In order to evaluate experimentally if the presence of hypertensive disease is an additional risk factor in connection with emergency situations including blood loss, awake spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) were subjected to standardized acute haemorrhage (35% of blood volume) via an aortic catheter. Mean arterial blood pressure (MAP), blood gases, acid-base balance, blood glucose and haematocrit values were followed and the 5-h survival rate was determined. In the early posthaemorrhagic phase similar plasma refill, as evidenced from haematocrit readings, was seen in SHR and WKY. Hyperglycaemia occurred in both groups but the hyperglycaemic response was only moderate and transient in SHR. The inability of SHR to maintain hyperglycaemia was intimately correlated to early appearance of metabolic acidosis and short posthaemorrhagic survival times. Determination of liver glycogen content of unbled SHR and WKY indicated that the deficient hyperglycaemic response in SHR was not due to inadequate glycogen stores but rather to poor liver perfusion resulting in liver hypoxia. Since spontaneous hypertension in rats in many ways is considered to be similar to essential hypertension in man, these findings suggest that human hypertensive disease constitutes a considerable risk factor in connection with acute haemorrhage.

Acid-Base Equilibrium↗
PubMed1983

Effects of haemorrhagic hypotension on brain and liver metabolism in normotensive (WKY) and spontaneously hypertensive rats (SHR).

Hypertensive disease is known to increase the risks in connection with acute changes in blood pressure due to the presence of pronounced structural as well as functional changes in the cardiovascular system. In the present study the metabolic consequences of fixed haemorrhagic hypotension [mean arterial pressure (MAP) 70 and 45 mmHg] were studied in spontaneously hypertensive (SHR) and in normotensive rats (WKY). Blood gases and acid-base balance, blood glucose, liver (ATP, glucose, lactate) and brain (ATP, ADP, AMP, CP, glucose, lactate) metabolites were determined in unbled animals and after 35 min hypotension in bled animals. In the liver haemorrhage to MAP 70 mmHg resulted in a 70% reduction of the ATP content in SHR while that in WKY remained unchanged. At MAP 45 mmHg reduced liver ATP levels (35% reduction) were observed in WKY as well. In the brain metabolic changes indicative of tissue ischaemia (reduced CP, increased AMP and lactate, decreased energy charge potential) were present only in SHR at MAP 45 mmHg. The more pronounced metabolic disturbances in SHR than in WKY indicate that blood loss is more deleterious for the hypertensive individual.

Animals↗
PubMed1983

Liver and skeletal muscle metabolism, extracellular K+ concentrations, and survival in spontaneously hypertensive rats following acute blood loss.

The metabolic responses of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) to acute blood loss (30% of the calculated blood volume) have been studied. The initial mean arterial pressure (MAP) was 179 mmHg in SHR and 105 mmHg in WKY. After bleeding, MAP decreased to about 50 mmHg in both groups. SHR failed to increase MAP in the posthemorrhagic period, while in WKY a level of 65-70 mmHg was reached. Metabolic changes in liver and skeletal muscle, indicative of tissue hypoxia, occurred earlier and were more pronounced in SHR than in WKY. In SHR, the ATP content of the liver was almost depleted within 1 h, while during the same time period only a moderate reduction was seen in WKY. Extracellular K+ concentration in sketetal muscle increased more rapidly in SHR than in WKY, but a similar relationship between lactate content and extracellular K+ concentration was found in both groups. The mean posthemorrhagic survival time was only 47 min for SHR, as compared to 193 min for WKY. The present results indicate that a blood loss is more detrimental for hypertensive than normotensive rats.

Acute Disease↗
PubMed1982

Effects of commercial (pH approximately 3.5) and freshly prepared (pH approximately 6.5) lidocaine-adrenaline solutions on tissue pH.

Differences in the effects of commercially available, sodium bisulfite-containing (pH 3.5-4), and freshly prepared (pH 6.5) lidocaine-adrenaline solutions on tissue pH and tissue oxygenation were studied experimentally. In rabbits, a 5 x 5 cm area under the panniculum was infiltrated with 0.9% NaCl, plain lidocaine, plain adrenaline or one of the two lidocaine-adrenaline solutions. Tissue pH was measured continuously as well as intermittently in the infiltrated area with monocrystalline antimony needle electrodes. Infiltration of the tissue with the 4 ml volume of a test solution did not seem to induce any significant tissue injury. Tissue pH was decreased for 30 min following plain lidocaine and for 90 min or more following lidocaine-adrenaline infiltration. With the exception of the first few minutes, no significant differences in the effects on tissue pH between commercial and freshly prepared lidocaine-adrenaline solutions could be seen. Tissue hypoxia occurred only following infiltration with plain adrenaline. It may thus be concluded that in spite of the low pH and the O2-reducing properties of commercial lidocaine-adrenaline solutions, a rapid buffering occurs in the tissues. The use of commercial lidocaine-adrenaline solution for local infiltration thus seems as safe as that of freshly prepared lidocaine-adrenaline solutions.

Animals↗
PubMed1980

Adamantinoma tibiae. A report of a new case.

This report describes a new case of adamantinoma of the tibia which is a rare primary malignant bone tumour. Just over 100 cases have been reported. The symptoms, treatment and problems of diagnosis are briefly discussed.

Aged↗